FIREBIRD PT

CAST (value AS TIMESTAMP) or CAST (value AS DATE) or CAST(value AS TIME) and same patter apply for any time.

Like Oracle Interbase/Firebird will automatically convert a string representation of a date/datetime to a date, however, you may CAST the string value to a date/date time explicitly by:

cast(‘2/1/2001′ as date)
cast(‘01-FEB-2001′ to date)
cast(NULL as date)
cast(‘TODAY’ | ‘YESTERDAY’ | ‘TOMMOROW’ | ‘NOW’ as date)
you also may add the time component
cast(‘01-FEB-2001:23:59:59′ to date)

var_Time = CAST(in_Date AS TIME);

var_ano = EXTRACT(YEAR FROM current_timestamp);

Diadasemana = EXTRACT(WEEKDAY FROM D);
vai retornar 0=Domingo, 1=Segunda, … 6=Sabado.
por outro lado, International Standard ISO 8601 especifica que a semana começa na Segunda-Feira e isso é dia 1. Para obter o Dia da Semanapelo padrão ISO, usa-se:
EXTRACT(WEEKDAY FROM D-1)+1;
que retorna 1=Segunda, 2=Terça, … 7=Domingo.

Exemplo:
SELECT
D,
EXTRACT( WEEKDAY FROM D) AS AMERICAN,
EXTRACT( WEEKDAY FROM D – 1) + 1 AS ISO8601
FROM T;